Duplex engine



(No Model.) 3 Sheets-Sheet 1.

A. J. CALDWELL.

DUPLEX ENGINE.

No. 596,981. Patented Jan. 11,1898.

(No Model.) beets-sheet 2 J. CALDWELL. DUPLEX ENGINE.

No. 596,981. Patented Jan. 11, 1898.

s SheetS -Sheet s;

m. E m m wn X Om T n A M d 0 M U m Patented Jan. 11, 1898.

class known as the \Vorthiugton duplex Unit-an Sterne Ferrari @rricn.

ANDREW J. Ci-lLDlVELL, OF BROOKLYN, NEW? YORK, ASSIG NOR TO THE HENRY R. YVORTHINGTON, OF ELIZABETH, NEW JERSEY.

DUPLEX Enema.

SPEOIFIGATIGN formingpart of Letters Patent No. 596,981, dated January 11, 1898. Application filed June 13, 1895. Serial No. 652,616. (No model.)

To (all whom may concern:

Be it known that 1, ANDREW J. CALDWELL, a citizen of the United States, residing at Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Duplex Engines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

This invention relates to duplex engines,

Jud especially to multiple-expansion engines of that class in which the steam is used expansively from one side of the engine to the other, as in triple and quadruple expansion engines and compound engines in which the highand low pressure cylinders are located on opposite sides of the engine.

The object of my invention is to provide a simple and eflicient construction of duplex engines in which the total effective power on the two sides of the engine may be readily adjusted as desired b Y power derived from an equalizingcylinder on one side of the engine, so that arcgular and uniform movement on both sides of the engine is secured, and especially to provide means whereby inequality of power on opposite sides of the engine shall be automatically corrected. In securing these results I employ a small equalizingcylin'der on one side of the engine, by which the power on that side of the engine may be increased or diminished and the relative power on the two sides of the engine thus adjusted as desired, this power-regulating cylinder forming a power-equalizing cylinder in constructions in which the invention is applied for securing equality of power on the two sides.

While the improvements forming my invention are of general application in all duplex engines in which the steam is used expansivclyfroin one side of the engine to the other side and it is desired to provide means for increasing the power on either side, so as to secure exactly the desired relative power on the two sides, the improvements have been designed in connection with an engine of the shown in many prior Letters Patent, of which especial reference is made herein to Patents N0s.283,26l,283,315, 292,525, 352,857, 341,534, dOlAOl, and 444,543.

As the invention rests chiefly in the general construction and arrangement of the engine, a full understanding of the same can best be given by an illustration and a somewhat detailed description of an engine embodying the invention as applied for equalizing the power on the opposite sides of the engine, and such description will now be given, reference being had to the accompanying drawings, forming a part of this specification, in Which Figure 1 is a side elevation of a horizontal duplex triple-expansion pumping engine embodying the improvements. Fig. 2 is a plan view of the same. Fig. 3 is a front elevation of the steam end. Fig. 4 is a plan view of the steam end of a compound duplex engine embodying my improvements, and Fig. 5 isa detail section of the valve controlling the supply of steam to the equalizing-cylinder.

Referring now to Figs. 1 to 3, the water end of the engine is of the ordinary construction, consisting of the water-cylinders A B, having plungers which are connected directly with the piston-rods on the opposite sides of the engine and provided with the usual suction and force chambers, which communicate, respectively, through the usual valves with the suction and force mains. At the steam end, in which the improvements forming the present invention are embodied, the engine is provided with a high-pressure cylinder O and intermediate cylinder D, forming one side of the engine and havingtheir pistons carried by the common piston-rod E, which is connected to the pump-piston in water-eylinderA. Upon the opposite side of the engine is the lowpressure cylinder F, having the piston-rod G, connected to the pump-plunger in water-cylinder B. A receiver I is provided, into which the intermediate cylinder exhaust-s and from which the low-pressure cylinder is supplied, this receiver being preferably placed, as shown, immediately under and forming asupport for the intermediate and lowpressure cylinders, and the high-pressure cylinder is preferably mounted on the end of the intermediate cylinder, so that the receiver forms a support for the entire steam end of the engine.

For the purpose of supplying any slight deficiency of pressure'upon the low pressure side of the engine and preserving a constant balance of efiective power between the two sides a small equalizing-cylinder H is placed upon the low-pressure side of the engine, the piston-rod G of the low-pressure cylinder being extended through the latter and carrying also the piston of the equalizing cylinder. This equalizing-cylinder may be supplied with steam from the receiver I; but it is preferably supplied with high-pressure steam from the boiler, as this supply may then be varied without interfering with the steam-supply to the low-pressure cylinder, and, moreover, a smaller equalizing-cylinder may thus be used.

All the cylinders are provided with the usual valves, which may be of any suitable construction, but are preferably of the rotary form shown in the Patents Nos. 401,401 and 444, 543, above referred to, and operated in the same manner as in these patents, the valvestems being connected by crank-arms to valve-rods 11. on opposite sides of the engine, and these valve-rods being connected to the usual valve-operating mechanism K between the steam and water ends, by which the valves upon one side of the engine are operated from the other side.

The high-pressure cylinder 0 receives its supply of steam from the supply pipe 12 through induction-pipe 13 and exhausts through exhaust-pipe 14 into the steam-chest of intermediate cylinder D. The intermediate cylinder D in turn exhausts through horizontal exhaust-pipe 15 and vertical pipe '16 into the receiver I, and this exhaust-steam passes from the receiver tothe low-pressure cylinder through pipe 16 and induction-pipe 17 of the low-pressure cylinder, the low-pressure cylinder in turn exhausting, as usual, through the pipe 18. The equalizing-cylinder H is supplied with high-pressure steam from the supply-pipe 12 through pipe 19, connecting with induction-pipe 20 of the equalizingcylinder, the equalizing-cylinder exhausting, preferably, into the receiver I through exhaust-pipe 21.

In order that the power upon opposite sides of the engine may be adjusted in first starting the engine and that any inequality of power resulting from variations in the running conditions of the engine may readily be corrected, it is necessary that means be provided for regulating the admission of steam to the equalizing-cylinder II, and for this purpose throttle 22 is provided on pipe 19 and a throttle 23 is preferably used on the induction-pipe 13 of cylinder G for adjusting the supply for the other cylinders of the engine, as usual.

The throttle 22 or any equivalent means for controlling the steam-supply to the equalizing-cylinder H by hand may be the only means of control used and an efficient construction produced, as any variations in the power on opposite sides of the engine may readily and quickly be corrected thereby. It

sides of the engine.

The pipe19 is controlled bya valve C6, the valve-rod 24 of which carries a piston 25,which moves in a cylinder 26, mounted in any suit able position the valve-rod 24 and valve a being normally pressed into position to close the valve by meansof a spring 27 pressing against the head of the cylinder 26 and a collar 28 on the valve-rod. The opposite ends of the cylinder 26 are connected by means of pipes 29 30 with, respectively, the steamchest of high-pressure cylinder 0 and the re ceiver I, the pressure in receiver I being applied to force the piston in adirection to close the valve a and the pressure from the high" pressure cylinder to open the valve. It is evident that the pressure within the receiver I is that of the low-pressure side of the engine, so that the valve a will be controlled in accordance with the relative pressures on the opposite sides of the engine, and in case of any excess or deficiency of pressure upon either side the piston will be actuated in the proper direction to admit more or less steam to the equalizing-cylinder, as the case may be, the spring 27 being graduated, preferably, so as to exert just the required pressure to overbalance the excess of pressure exerted on one side of the piston 25 by the high-pressure steam from the pipe 29 when the power upon the opposite sides is equal and hold the valve normally closed.

It is desirable that some steam should be admitted to the equalizing-cylinder H at all times to keep the parts in proper condition, and this result may be attained by properly constructing the valve so as to form a bypass. In the construction shown, however, I provide a by-pass 1 around the valve or, which is preferably controlled by a cock 2, so that a fine adjustment of the amount of steam normally admitted to the equalizing-cylinder may be obtained. A

The operation of the engine with the automatic control of the equalizing-cylinder will be understood without further description, it being evident that the pressure in the equalizing-cylinder H is under the control of the pressure on the two sides of the engine, so that any deficiency of pressure on either side of the engide due to changes in water-pressure or other causes will be immediately compensated for by increase or decrease in the supply of steam to the equalizing-cylinder II, and a perfect uniformity of action on the two sides of the engine is secured.

In Fig. 4 I have shown my improvements IIO , ceives its steam from the receiver 1 and highpressure cylinder 0 through the same connections as previously used from the intermediate cylinder, and all the connections between the equalizing-cylinder and other parts of the engine are the same as previously described. It is evident also that the use of the equalizing-cylinder construction shown is not limited to compound and triple-expansion engines, but that it may readily be applied to all duplex multiple-expansion engines in Which the steam is used expansively from one side oi the engine to the other. Thus in the quadruple expansion engine shown in Patent No. 283,315, above referred to, the equalizing-cylinder may be added on the low-pressure side and its supply taken from the boiler or receiver 11. If the supply be taken from the receiver,-itwill retard the high-pressure sideas Well as assist the lowpressure side, the regulating eitect of a slight variation in the supply thus being increased.

The application of my improvements to other engines of the general duplex class will be understood Without further illustration or description. It will be understood also that modifications may readily. be made in the general arrangement and detail construction shown Without departing from my invention.

VVha-t I claim isl. A multiple-expansion duplex engine having apowerrequalizing cylinder on the Weaker side, substantially as described.

2. A multiple-expansion duplex engine having a power-equalizing high-pressure cylinder on the low-pressure side, substantially as described.

3. Amultiple-expansion duplex engine having a power-equalizing cylinder on the lowpressure side and provided with means for regulating the supply of steam to the equalicing-cylinder in accordance with the variations of pressure on the opposite sides of the engine, substantially as described.

l. Amultiple-expansion duplex engine having a power-equalizing cylinder on the lowpressure side, and provided with means for automatically regulating the supply of steam to the equalizing-cylinderin accordance with the variations of pressure on the opposite sides of the engine, substantially as described.

5. The combination with a multiple-expansion duplex engine having a power-equalizing cylinder on the low-pressure side, of a valve controlling the supply of steam to the equalizing cylinder, and means for applying to said valve the pressure on the low-pressure side of the engine to close the valve, substantially as described.

6. The combination with a multiple-expansion duplex engine having a power-equalizing cylinder on the Weaker side, of a valve controlling the supply of steam to the equalizing-cylinder,and means for applying the pressure on the opposite sides of the engine to move the valve in opposite directions, whereby the valve is controlled in accordance with the relative pressures on the opposite sides of the engine, substantially as described.

7. The combination with a multiple-expansion duplex engine having a poWer-regulat ing cylinder on one side, of avalve' controlling the supply of steam to the regulating cylinder, and means for applying the pressure on the opposite sides of the engine to move the valve in opposite directions, whereby the valve is controlled in accordance with the relative pressures on the opposite sides of the engine, substantially as described.

8. The combination with a multiple-expan sion duplex engine having a power-regulating cylinder on one side, of supply-pipe 19 for said regulating-cylinder, valve a controlling said pipe, and piston 25 connected to said valve and pressed in the direction to close the valve by the pressure on the powerregulating-cylinder side of the engine, substantially as described.

9. The combination with a multiple-expansion duplex engine having a power-regulating cylinder on one side, of a supply-pipe 19 for said regulating-cylinder, valve a controlling said pipe, and piston 25 connected to said valve and subjected on opposite sides to the pressure on opposite sides of the engine, the

pressure on the power-regulating-cylinder side tending to close the valve, substantially as described.

10. The combination with a multiple-expansion duplex engine having a poWer-regw lating cylinder on one side, of supply-pipe 19 for the regulating-cylinder, valve a controlling said pipe, piston :25 connected to said valve and subjected on opposite sides to the pressure on opposite sides of the engine, the pressure on the power-regulatingcylinder side tending to close the valve, and a spring aiding the pressure on the power-regulatingcylinder side, substantially as described.

11. The combination with a multiple-expansion duplex engine having a poWer-regw lating cylinder on one side, supply-pipe 19 for the regulating-cylinder, valve or controlling said pipe, piston 25 connected to said Valve and subjected on opposite sides to the pressure on oppositesides of the engine, the

IIO

pressure on the power-regulating-cylinder side tending to close the valve, and a by-pass for admitting a constant supply of steam past said valve, substan tially as described.

12. The combination with a multiple-expansion duplex engine having a receiver through which the exhaust of one side passes to the other side, of a high-pressure-equalizing cylinder on the side receiving the exhaust, said equalizing-cylinder exhausting into the receiver, substantially as described.

13. A multiple-expansion duplex engine 16. A duplex engine having a power-regulating cylinder on one side and provided with means for automatically regulating the supply of steam to the regulating-cylinder in accordance With the Variations of pressure on the opposite sides of the engine, substantially as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

ANDREW J. CALDWELL.

Witnesses:

B. W. PIERSON, ALEXANDER D. CHEW.

Corrections in Letters Patent No. 596,981.

It is hereby certified that in Letters Patent No. 596,981 granted January 11, 1898,

: upon the application of Andrew J Caldwell, of Brooklyn, New York, for an improve- 2 ment in Duplex Engines, errors appear in the printed specification requiring correetion, as follows: On page 1, lines 23 and 29, the Word equalizing should read auxiliary; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofilce.

Signed, countersignecl, and sealed this 1st day of February, A. 1)., 1898.

WEBSTER DAVIS, Assistant Secretary of the Interior.

[SEAL] Gountersigned:

A. P. GREELEY,

Acting Commissioner of Patents. 

